Radius dresser



June 13, 1967 E. KOCH 3,324,843

RADIUS DRESSER Filed March 1, 1965 3 sheets sheet 1 INVENTOR. fl/GHVE KOCH mfm.

ATTORNEYS.

June 13, 1967 E. KocH 1 3,324,843

RADIUS DRES SER Filed March 1, 1965 3 heets-Sheet 2 I N VEN TOR. fUGf/VE' #06 ATTORNEY? June 13, 1967 oc 3,324,843

RADIUS DRESSER Filed March 1, 1965 3 SheetsSheet 3 Fig. 3

ATTOQNEKS'.

United States Patent 3,324,843 RADIUS DRESSER Eugene Koch, Roseville, Mich, assignor to MS&R lincorporated, Irwin, Pa., a corporation of Pennsylvania Filed Mar. 1, 1965, Ser. No. 435,868 7 Claims. ((1 125--11) This invention relates to tools for dressing transversely concave and convex peripheries on wheels, such as grinding Wheels, for example.

In order for a grinding wheel to form a crown on an object, the grinding face of the wheel should be concave transversely. The concavity should have the same radius as the convex surface that is to be formed. Likewise, a concavity can be formed in an object by using a grinding wheel that has a crowned grinding face. In either case, the face of the grinding wheel must first be dressed to the desired contour. As it becomes worn with use, its contour is changed. To return it to its original contour, it is necessary to dress the wheel. Both the original and the subsequent dressing are generally done by moving back and forth across the face of the wheel a dressing tool that is pivoted so that it will swing in the same arc as the one to be formed on the wheel. In the past, there has been no difiiculty with this arrangement as long as the radius of the surface being dressed is short enough to permit the dressing tool to be pivoted on its support. However, for a longer radius, which means a flatter arc, there is no convenient place to pivot the tool.

It is among the objects of this invention to provide a radius dresser which can be used to dress arcs of any male or female radius beyond a predetermined minimum, which is compact, which is easy to adjust, which is simple in construction and operation, and which can dress a straight surface (infinite radius).

In accordance with this invention, a pair of laterally spaced guide members are mounted on the front end of a base. Movable in all directions on the base behind these members is a slide, on which a forwardly and backwardly adjustable tool holder is mounted midway between the opposite sides of the slide. A dressing tool is supported by the holder and projects from the front of it. Engaging the front of the tool holder are the inner ends of a pair of arms that extend laterally of the slide away from each other and have straight front faces. The outer ends of the arms are pivoted to the slide on vertical axes. When the inner ends of the arms are midway between the guide members, the arms are long enough to extend outwardly beyond those members. By moving the slide back and forth laterally across the base while the front faces of its arms are held in engagement with the guide members, the dressing tool will be carried in a predetermined path that is determined by the position of the tool holder on the slide. The path of the dressing tool is controlled by the points of engagement of the arms with the guide members. Thus, for example, if the tool holder is adjusted to a position where the front faces of the two arms are in forwardly converging relation, the tool will dress a concave face on a rotating grinding wheel positioned in front of the base and engaged by the tool.

The preferred embodiment of the invention is illustrated in the accompanying drawings, in which FIG. 1 is a plan view of my radius dresser;

FIG. 2 is a view of the front end of the dresser;

FIG. 3 is a vertical longitudinal section taken on the line l II-III of FIG. 1; and

FIG. 4 is a fragmentary horizontal section of the tool holder, showing the inner ends of the arms.

Referring to the drawings, a base plate 1 (FIGS. 2 and 3) is provided that can be moved forward and backward relative to a grinding wheel 2, for example, that "ice is to be dressed and therefore is mounted in front of the plate on a spindle 3 that may be driven in any suitable manner. The base plate may be supported by a magnetic chuck 4 and either fed ahead by suitable chuck-driving means or pushed ahead manually on the chuck. In the latter case, the bottom of the base preferably is provided at one side with a pair of corner recesses, in which locating buttons 6 are rigidly mounted and from which they project into sliding engagement with one side of a straight rib 7 that extends along one side of the top of the chuck. The buttons and rib form a guide for the base so that it can be moved in a perfectly straight line. Mounted on the two front corners of the base are a pair of guide members 8, that preferably are formed by rollers having vertical axes.

Resting on top of the base behind rollers 8 is a slide 11 that can be moved in all directions over the base. Preferably, a wear plate 12 is mounted on the base plate for engagement by the bottom of the slide. The shape of the slide can take various forms. The slide shown in FIG. 1 has a central body extending lengthwise of the base and integral wings extending outwardly beyond the opposite sides of the base. Pivoted on vertical pivot pins 13 in the outer ends of these wings are the outer ends of a pair of arms 14 that extend inwardly toward each other and nearly meet midway between the opposite sides of the slide. The front faces of the arms are straight, throughout most of their length at least.

Behind the inner ends of the arms a tool holder 16 is mounted on the slide. The holder may project down into a straight channel 17 that extends from front to back of the slide and along which the holder can slide. It can be held in any desired position along the channel by means of a set screw 18 that extends down through a longitudinal vertical slot 19 in the holder and is screwed into the slide beneath it. The head of the screw engages the top of the tool holder to clamp the holder tightly onto the slide. The front of the tool holder, which preferably extends upwardly above the rest of the holder, is provided in its upper end with a horizontal bore, in which a dressing tool 21 is slidably mounted but held in any desired position by a set screw 22. The point of the tool projects from the front of the holder. The position of the tool holder on the slide determines the arc in which the dressing tool can be moved, as will be explained presently. But first, to correctly position the holder for the desired tool arc, a gauge block '23 may be placed behind it in engagement With an abutment 24 mounted on the rear end of the slide. While the block is in place, the tool holder is moved back against it and then set screw 18 is tightened to lock the tool holder in place.

In order to use this equipment after the tool holder has been set in proper position on the slide by means of a gauge block, the slide is moved forward on the base until the straight front faces of the arms engage rollers 8 in front of them. The inner ends of the arms must engage the front of the tool holder 16. In fact, it is preferred that the arms always be pressed against the tool holder, even when they do not engage the guide rollers, and this can be accomplished by suitable springs, such as torsion springs 26 wound on the drum-like heads of pivot pins 13. One end of each spring is anchored in the pin, and the other end projects into a hole 27 in the underlying arm. The slide then is moved slowly back and forth across the base while the front of its arms are pressed against the guide rollers. It will be seen that when the front faces of the two arms are inclined forward and toward the center of the slide, as shown in FIG. 1, movement of the arms back and forth across the guide rollers at least as far as the dotted line positions indicated in that figure will cause the slide to swing back and forth and thereby carry the dressing tool 21 in an arcuate path that will dress a transversely concave face on the grinding wheel that it engages. As the dressing proceeds, the base and slide are fed forward-until the desired surface has been formed on the wheel. Any danger of the slide being moved too far to one side or the other can be avoided by providing the outer ends of the lateral extremities of the slide with forwardly projecting ears 28 that will engage the guide rollers and serve as stops.

It will be seen that this radius dresser does not require a fixed pivot point around which the dressing tool is swung, so that the radius of the are being dressed can 'be infinitely long. In fact, by adjusting the tool holder to bring the front faces of arms 14 into a straight line, the wheel 2 can be provided with a perfectly cylindrical face. It also will be observed that this dresser is simple in construction and easy to operate.

In order to form a crown on wheel 2, all that has to be done is to back up the tool holder on the slide until the front faces of the pivoted arms converge toward the back of the slide. When the slide then is moved back and forth across the base, with the arms in engagement with the guide rollers, the dressing tool will move in a concave path across the wheel. The curvature of the arc will depend on the size of gauge block inserted between abutment 24 and the rear end of the tool holder.

By using the sine bar method and placing a gauge block between one of the locating buttons 6 and rib 7 in order to tilt base plate 1 laterally in one direction or the other, the wheel 2 can be dressed at an angle.

According to the provisions of the patent statutes, I have explained the principle of my invention and have illustrated and described what I now consider to represent its best embodiment. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

I claim:

1. A radius dresser comprising a base having a front end, a pair of laterally spaced guide members mounted on said front end, a slide movable in all directions on the base behind said members, a forwardly and backwardly adjustable tool holder mounted on the slide midway between its opposite sides, a dressing tool projecting from the front of said holder, a pair of arms having 4 inner ends engaging the front of the tool holder, the arms extending laterally of said slide away from each other and having straight front faces, and means pivoting the outer ends of the arms to the slide on vertical axes, the arms extending outwardly beyond the guide members when their inner ends are midway between said members, and said slide being adapted to be moved back and forth laterally across the base with the front faces of the arms in engagement with said guide members, whereby to reciprocate said tool in a predetermined dressing path determined by the position of the tool holder on the slide.

2. A radius dresser according to claim 1, including resilient means holding the inner ends of said arms against the front of said tool holder.

3. A radius dresser according to claim 1, in which said guide members are rollers having vertical axes.

4. A radius dresser according to claim 1, in which said tool holder has a vertical slot therethrough extending forward and backward, and a vertical set screw extends through the slot and is screwed into said slide, the screw having a head bearing against the top of said holder.

5. A radius dresser according to claim 1, in which the slide is provided adjacent the outer ends of said arms with forwardly projecting portions serving as stops that can engage said contact members to limit lateral movement of the slide across said base.

6. A radius dresser according to claim 1, in which said slide extends behind said tool holder and is provided with a vertical abutment spaced from the holder, whereby a gauge block can be inserted between the holder and abutment in engagement with both to locate the tool holder in the desired position on the slide.

7. A radius dresser according to claim 1, in which said base is provided at one side with a pair of laterally projecting arcuate surfaces spaced lengthwise thereof for sliding engagement with a straight guide wall also extending lengthwise of the base.

References Cited UNITED STATES PATENTS HAROLD D. WHITEHEAD, Primary Examiner. 

1. A RADIUS DRESSER COMPRISING A BASE HAVING A FRONT END, A PAIR OF LATERALLY SPACED GUIDE MEMBERS MOUNTED ON SAID FRONT END, A SLIDE MOVABLE IN ALL DIRECTIONS ON THE BASE BEHIND SAID MEMBERS, A FORWARDLY AND BACKWARDLY ADJUSTABLE TOOL HOLDER MOUNTED ON THE SLIDE MIDWAY BETWEEN ITS OPPOSITE SIDES, A DRESSING TOOL PROJECTING FROM THE FRONT OF SAID HOLDER, A PAIR OF ARMS HAVING INNER ENDS ENGAGING THE FRONT OF THE TOOL HOLDER, THE ARMS EXTENDING LATERALLY OF SAID SLIDE AWAY FROM EACH OTHER AND HAVING STRAIGHT FRONT FACES, AND MEANS PIVOTING THE OUTER ENDS OF THE ARMS TO THE SLIDE ON VERTICAL AXES, THE ARMS EXTENDING OUTWARDLY BEYOND THE GUIDE MEMBERS WHEN THEIR INNER ENDS ARE MIDWAY BETWEEN SAID MEMBERS, AND SAID SLIDE BEING ADAPTED TO BE MOVED BACK AND FORTH LATERALLY ACROSS THE BASE WITH THE FRONT FACES OF THE ARMS IN ENGAGEMENT WITH SAID GUIDE MEMBERS, WHEREBY TO RECIPROCATE SAID TOOL IN A PREDETERMINED DRESSING PATH DETERMINED BY THE POSITION OF THE TOOL HOLDER ON THE SLIDE. 